DESCRIPTION: Our proposed project, Gold nanoparticle-based mercury analyzer for on-site measurement of soil and sediment, will develop and test the feasibility of nanoparticle- based mercury sensors for on-site measurements. Our focus is on adapting the technique to accommodate soil and sediment samples from contaminated sites. Immediate, highly accurate, and sensitive measurements of mercury contamination at sites are the best option. But the high-cost, low portability and low sensitivity of the available instruments often force investigators to collect samples and send them to labs to be analyzed. Gold nanoparticle-based plasmonic mercury sensing is inexpensive, ultra-sensitive, and ideal for portable applications. Using off-the-shelf components, Picoyune will design and build a lightweight (<20 lbs) and low power sensor that can replace time consuming and costly laboratory methods. The prototype sensor will be tested for feasibility and compared to the other commercial options. The development of such a commercial analyzer will benefit those parties concerned with monitoring and remediation of contaminated sites as well as all groups who monitor mercury. Mercury monitoring costs hundreds of millions of dollars each year across diverse scientific, regulatory, and industrial groups. The fundamental issue they all face is protecting human health and the environment from the risks of mercury pollution.